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naiveproxy/net/quic/core/quic_connection.cc
klzgrad 19bc836227 Import chromium-63.0.3239.132
2018-01-29 00:30:36 +08:00

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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/quic/core/quic_connection.h"
#include <string.h>
#include <sys/types.h>
#include <algorithm>
#include <iterator>
#include <limits>
#include <memory>
#include <set>
#include <utility>
#include "base/format_macros.h"
#include "base/macros.h"
#include "base/metrics/histogram_macros.h"
#include "net/base/net_errors.h"
#include "net/quic/core/crypto/crypto_protocol.h"
#include "net/quic/core/crypto/quic_decrypter.h"
#include "net/quic/core/crypto/quic_encrypter.h"
#include "net/quic/core/proto/cached_network_parameters.pb.h"
#include "net/quic/core/quic_bandwidth.h"
#include "net/quic/core/quic_config.h"
#include "net/quic/core/quic_packet_generator.h"
#include "net/quic/core/quic_pending_retransmission.h"
#include "net/quic/core/quic_utils.h"
#include "net/quic/platform/api/quic_bug_tracker.h"
#include "net/quic/platform/api/quic_flag_utils.h"
#include "net/quic/platform/api/quic_flags.h"
#include "net/quic/platform/api/quic_logging.h"
#include "net/quic/platform/api/quic_map_util.h"
#include "net/quic/platform/api/quic_str_cat.h"
#include "net/quic/platform/api/quic_text_utils.h"
using std::string;
namespace net {
class QuicDecrypter;
class QuicEncrypter;
namespace {
// The largest gap in packets we'll accept without closing the connection.
// This will likely have to be tuned.
const QuicPacketNumber kMaxPacketGap = 5000;
// Maximum number of acks received before sending an ack in response.
// TODO(fayang): Remove this constant when deprecating QUIC_VERSION_38.
const QuicPacketCount kMaxPacketsReceivedBeforeAckSend = 20;
// Maximum number of consecutive sent nonretransmittable packets.
const QuicPacketCount kMaxConsecutiveNonRetransmittablePackets = 19;
// Maximum number of retransmittable packets received before sending an ack.
const QuicPacketCount kDefaultRetransmittablePacketsBeforeAck = 2;
// Minimum number of packets received before ack decimation is enabled.
// This intends to avoid the beginning of slow start, when CWNDs may be
// rapidly increasing.
const QuicPacketCount kMinReceivedBeforeAckDecimation = 100;
// Wait for up to 10 retransmittable packets before sending an ack.
const QuicPacketCount kMaxRetransmittablePacketsBeforeAck = 10;
// One quarter RTT delay when doing ack decimation.
const float kAckDecimationDelay = 0.25;
// One eighth RTT delay when doing ack decimation.
const float kShortAckDecimationDelay = 0.125;
// Error code used in WriteResult to indicate that the packet writer rejected
// the message as being too big.
const int kMessageTooBigErrorCode = ERR_MSG_TOO_BIG;
bool Near(QuicPacketNumber a, QuicPacketNumber b) {
QuicPacketNumber delta = (a > b) ? a - b : b - a;
return delta <= kMaxPacketGap;
}
// An alarm that is scheduled to send an ack if a timeout occurs.
class AckAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit AckAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
void OnAlarm() override {
DCHECK(connection_->ack_frame_updated());
QuicConnection::ScopedPacketBundler bundler(connection_,
QuicConnection::SEND_ACK);
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(AckAlarmDelegate);
};
// This alarm will be scheduled any time a data-bearing packet is sent out.
// When the alarm goes off, the connection checks to see if the oldest packets
// have been acked, and retransmit them if they have not.
class RetransmissionAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit RetransmissionAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
void OnAlarm() override { connection_->OnRetransmissionTimeout(); }
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(RetransmissionAlarmDelegate);
};
// An alarm that is scheduled when the SentPacketManager requires a delay
// before sending packets and fires when the packet may be sent.
class SendAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit SendAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
void OnAlarm() override { connection_->WriteAndBundleAcksIfNotBlocked(); }
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(SendAlarmDelegate);
};
class TimeoutAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit TimeoutAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
void OnAlarm() override { connection_->CheckForTimeout(); }
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(TimeoutAlarmDelegate);
};
class PingAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit PingAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
void OnAlarm() override { connection_->OnPingTimeout(); }
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(PingAlarmDelegate);
};
class MtuDiscoveryAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit MtuDiscoveryAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
void OnAlarm() override { connection_->DiscoverMtu(); }
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(MtuDiscoveryAlarmDelegate);
};
} // namespace
#define ENDPOINT \
(perspective_ == Perspective::IS_SERVER ? "Server: " : "Client: ")
QuicConnection::QuicConnection(
QuicConnectionId connection_id,
QuicSocketAddress address,
QuicConnectionHelperInterface* helper,
QuicAlarmFactory* alarm_factory,
QuicPacketWriter* writer,
bool owns_writer,
Perspective perspective,
const QuicTransportVersionVector& supported_versions)
: framer_(supported_versions,
helper->GetClock()->ApproximateNow(),
perspective),
helper_(helper),
alarm_factory_(alarm_factory),
per_packet_options_(nullptr),
writer_(writer),
owns_writer_(owns_writer),
encryption_level_(ENCRYPTION_NONE),
clock_(helper->GetClock()),
random_generator_(helper->GetRandomGenerator()),
connection_id_(connection_id),
peer_address_(address),
active_peer_migration_type_(NO_CHANGE),
highest_packet_sent_before_peer_migration_(0),
last_packet_decrypted_(false),
last_size_(0),
current_packet_data_(nullptr),
last_decrypted_packet_level_(ENCRYPTION_NONE),
should_last_packet_instigate_acks_(false),
was_last_packet_missing_(false),
largest_seen_packet_with_ack_(0),
largest_seen_packet_with_stop_waiting_(0),
max_undecryptable_packets_(0),
pending_version_negotiation_packet_(false),
save_crypto_packets_as_termination_packets_(false),
idle_timeout_connection_close_behavior_(
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET),
close_connection_after_five_rtos_(false),
close_connection_after_three_rtos_(false),
received_packet_manager_(&stats_),
ack_queued_(false),
num_retransmittable_packets_received_since_last_ack_sent_(0),
last_ack_had_missing_packets_(false),
num_packets_received_since_last_ack_sent_(0),
stop_waiting_count_(0),
ack_mode_(TCP_ACKING),
ack_decimation_delay_(kAckDecimationDelay),
unlimited_ack_decimation_(false),
delay_setting_retransmission_alarm_(false),
pending_retransmission_alarm_(false),
defer_send_in_response_to_packets_(false),
ping_timeout_(QuicTime::Delta::FromSeconds(kPingTimeoutSecs)),
arena_(),
ack_alarm_(alarm_factory_->CreateAlarm(arena_.New<AckAlarmDelegate>(this),
&arena_)),
retransmission_alarm_(alarm_factory_->CreateAlarm(
arena_.New<RetransmissionAlarmDelegate>(this),
&arena_)),
send_alarm_(
alarm_factory_->CreateAlarm(arena_.New<SendAlarmDelegate>(this),
&arena_)),
resume_writes_alarm_(
alarm_factory_->CreateAlarm(arena_.New<SendAlarmDelegate>(this),
&arena_)),
timeout_alarm_(
alarm_factory_->CreateAlarm(arena_.New<TimeoutAlarmDelegate>(this),
&arena_)),
ping_alarm_(
alarm_factory_->CreateAlarm(arena_.New<PingAlarmDelegate>(this),
&arena_)),
mtu_discovery_alarm_(alarm_factory_->CreateAlarm(
arena_.New<MtuDiscoveryAlarmDelegate>(this),
&arena_)),
visitor_(nullptr),
debug_visitor_(nullptr),
packet_generator_(connection_id_,
&framer_,
random_generator_,
helper->GetStreamFrameBufferAllocator(),
this),
idle_network_timeout_(QuicTime::Delta::Infinite()),
handshake_timeout_(QuicTime::Delta::Infinite()),
time_of_last_received_packet_(clock_->ApproximateNow()),
time_of_last_sent_new_packet_(clock_->ApproximateNow()),
last_send_for_timeout_(clock_->ApproximateNow()),
sent_packet_manager_(
perspective,
clock_,
&stats_,
FLAGS_quic_reloadable_flag_quic_default_to_bbr ? kBBR : kCubicBytes,
kNack),
version_negotiation_state_(START_NEGOTIATION),
perspective_(perspective),
connected_(true),
can_truncate_connection_ids_(true),
mtu_discovery_target_(0),
mtu_probe_count_(0),
packets_between_mtu_probes_(kPacketsBetweenMtuProbesBase),
next_mtu_probe_at_(kPacketsBetweenMtuProbesBase),
largest_received_packet_size_(0),
goaway_sent_(false),
goaway_received_(false),
write_error_occurred_(false),
no_stop_waiting_frames_(false),
consecutive_num_packets_with_no_retransmittable_frames_(0) {
QUIC_DLOG(INFO) << ENDPOINT
<< "Created connection with connection_id: " << connection_id;
framer_.set_visitor(this);
stats_.connection_creation_time = clock_->ApproximateNow();
// TODO(ianswett): Supply the NetworkChangeVisitor as a constructor argument
// and make it required non-null, because it's always used.
sent_packet_manager_.SetNetworkChangeVisitor(this);
// Allow the packet writer to potentially reduce the packet size to a value
// even smaller than kDefaultMaxPacketSize.
SetMaxPacketLength(perspective_ == Perspective::IS_SERVER
? kDefaultServerMaxPacketSize
: kDefaultMaxPacketSize);
received_packet_manager_.set_max_ack_ranges(255);
}
QuicConnection::~QuicConnection() {
if (owns_writer_) {
delete writer_;
}
ClearQueuedPackets();
}
void QuicConnection::ClearQueuedPackets() {
for (QueuedPacketList::iterator it = queued_packets_.begin();
it != queued_packets_.end(); ++it) {
// Delete the buffer before calling ClearSerializedPacket, which sets
// encrypted_buffer to nullptr.
delete[] it->encrypted_buffer;
ClearSerializedPacket(&(*it));
}
queued_packets_.clear();
}
void QuicConnection::SetFromConfig(const QuicConfig& config) {
if (config.negotiated()) {
// Handshake complete, set handshake timeout to Infinite.
SetNetworkTimeouts(QuicTime::Delta::Infinite(),
config.IdleNetworkTimeout());
if (config.SilentClose()) {
idle_timeout_connection_close_behavior_ =
ConnectionCloseBehavior::SILENT_CLOSE;
}
} else {
SetNetworkTimeouts(config.max_time_before_crypto_handshake(),
config.max_idle_time_before_crypto_handshake());
}
sent_packet_manager_.SetFromConfig(config);
if (config.HasReceivedBytesForConnectionId() &&
can_truncate_connection_ids_) {
packet_generator_.SetConnectionIdLength(
config.ReceivedBytesForConnectionId());
}
max_undecryptable_packets_ = config.max_undecryptable_packets();
if (config.HasClientSentConnectionOption(kMTUH, perspective_)) {
SetMtuDiscoveryTarget(kMtuDiscoveryTargetPacketSizeHigh);
}
if (config.HasClientSentConnectionOption(kMTUL, perspective_)) {
SetMtuDiscoveryTarget(kMtuDiscoveryTargetPacketSizeLow);
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSetFromConfig(config);
}
if (config.HasClientSentConnectionOption(kACKD, perspective_)) {
ack_mode_ = ACK_DECIMATION;
}
if (config.HasClientSentConnectionOption(kAKD2, perspective_)) {
ack_mode_ = ACK_DECIMATION_WITH_REORDERING;
}
if (config.HasClientSentConnectionOption(kAKD3, perspective_)) {
ack_mode_ = ACK_DECIMATION;
ack_decimation_delay_ = kShortAckDecimationDelay;
}
if (config.HasClientSentConnectionOption(kAKD4, perspective_)) {
ack_mode_ = ACK_DECIMATION_WITH_REORDERING;
ack_decimation_delay_ = kShortAckDecimationDelay;
}
if (FLAGS_quic_reloadable_flag_quic_ack_decimation) {
QUIC_FLAG_COUNT(quic_reloadable_flag_quic_ack_decimation);
if (config.HasClientSentConnectionOption(kAKDU, perspective_)) {
unlimited_ack_decimation_ = true;
}
}
if (config.HasClientSentConnectionOption(k5RTO, perspective_)) {
close_connection_after_five_rtos_ = true;
}
if (FLAGS_quic_reloadable_flag_quic_enable_3rtos &&
config.HasClientSentConnectionOption(k3RTO, perspective_)) {
QUIC_FLAG_COUNT(quic_reloadable_flag_quic_enable_3rtos);
close_connection_after_three_rtos_ = true;
}
if (transport_version() > QUIC_VERSION_37 &&
config.HasClientSentConnectionOption(kNSTP, perspective_)) {
no_stop_waiting_frames_ = true;
}
}
void QuicConnection::OnSendConnectionState(
const CachedNetworkParameters& cached_network_params) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSendConnectionState(cached_network_params);
}
}
void QuicConnection::OnReceiveConnectionState(
const CachedNetworkParameters& cached_network_params) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnReceiveConnectionState(cached_network_params);
}
}
void QuicConnection::ResumeConnectionState(
const CachedNetworkParameters& cached_network_params,
bool max_bandwidth_resumption) {
sent_packet_manager_.ResumeConnectionState(cached_network_params,
max_bandwidth_resumption);
}
void QuicConnection::SetMaxPacingRate(QuicBandwidth max_pacing_rate) {
sent_packet_manager_.SetMaxPacingRate(max_pacing_rate);
}
void QuicConnection::SetNumOpenStreams(size_t num_streams) {
sent_packet_manager_.SetNumOpenStreams(num_streams);
}
bool QuicConnection::SelectMutualVersion(
const QuicTransportVersionVector& available_versions) {
// Try to find the highest mutual version by iterating over supported
// versions, starting with the highest, and breaking out of the loop once we
// find a matching version in the provided available_versions vector.
const QuicTransportVersionVector& supported_versions =
framer_.supported_versions();
for (size_t i = 0; i < supported_versions.size(); ++i) {
const QuicTransportVersion& version = supported_versions[i];
if (QuicContainsValue(available_versions, version)) {
framer_.set_version(version);
return true;
}
}
return false;
}
void QuicConnection::OnError(QuicFramer* framer) {
// Packets that we can not or have not decrypted are dropped.
// TODO(rch): add stats to measure this.
if (!connected_ || last_packet_decrypted_ == false) {
return;
}
CloseConnection(framer->error(), framer->detailed_error(),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
void QuicConnection::OnPacket() {
last_packet_decrypted_ = false;
}
void QuicConnection::OnPublicResetPacket(const QuicPublicResetPacket& packet) {
// Check that any public reset packet with a different connection ID that was
// routed to this QuicConnection has been redirected before control reaches
// here. (Check for a bug regression.)
DCHECK_EQ(connection_id_, packet.public_header.connection_id);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPublicResetPacket(packet);
}
const string error_details = "Received public reset.";
QUIC_DLOG(INFO) << ENDPOINT << error_details;
TearDownLocalConnectionState(QUIC_PUBLIC_RESET, error_details,
ConnectionCloseSource::FROM_PEER);
}
bool QuicConnection::OnProtocolVersionMismatch(
QuicTransportVersion received_version) {
QUIC_DLOG(INFO) << ENDPOINT << "Received packet with mismatched version "
<< received_version;
// TODO(satyamshekhar): Implement no server state in this mode.
if (perspective_ == Perspective::IS_CLIENT) {
const string error_details = "Protocol version mismatch.";
QUIC_BUG << ENDPOINT << error_details;
TearDownLocalConnectionState(QUIC_INTERNAL_ERROR, error_details,
ConnectionCloseSource::FROM_SELF);
return false;
}
DCHECK_NE(transport_version(), received_version);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnProtocolVersionMismatch(received_version);
}
switch (version_negotiation_state_) {
case START_NEGOTIATION:
if (!framer_.IsSupportedVersion(received_version)) {
SendVersionNegotiationPacket();
version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
return false;
}
break;
case NEGOTIATION_IN_PROGRESS:
if (!framer_.IsSupportedVersion(received_version)) {
SendVersionNegotiationPacket();
return false;
}
break;
case NEGOTIATED_VERSION:
// Might be old packets that were sent by the client before the version
// was negotiated. Drop these.
return false;
default:
DCHECK(false);
}
version_negotiation_state_ = NEGOTIATED_VERSION;
visitor_->OnSuccessfulVersionNegotiation(received_version);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(received_version);
}
QUIC_DLOG(INFO) << ENDPOINT << "version negotiated " << received_version;
// Store the new version.
framer_.set_version(received_version);
// TODO(satyamshekhar): Store the packet number of this packet and close the
// connection if we ever received a packet with incorrect version and whose
// packet number is greater.
return true;
}
// Handles version negotiation for client connection.
void QuicConnection::OnVersionNegotiationPacket(
const QuicVersionNegotiationPacket& packet) {
// Check that any public reset packet with a different connection ID that was
// routed to this QuicConnection has been redirected before control reaches
// here. (Check for a bug regression.)
DCHECK_EQ(connection_id_, packet.connection_id);
if (perspective_ == Perspective::IS_SERVER) {
const string error_details = "Server receieved version negotiation packet.";
QUIC_BUG << error_details;
TearDownLocalConnectionState(QUIC_INTERNAL_ERROR, error_details,
ConnectionCloseSource::FROM_SELF);
return;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnVersionNegotiationPacket(packet);
}
if (version_negotiation_state_ != START_NEGOTIATION) {
// Possibly a duplicate version negotiation packet.
return;
}
if (QuicContainsValue(packet.versions, transport_version())) {
const string error_details =
"Server already supports client's version and should have accepted the "
"connection.";
QUIC_DLOG(WARNING) << error_details;
TearDownLocalConnectionState(QUIC_INVALID_VERSION_NEGOTIATION_PACKET,
error_details,
ConnectionCloseSource::FROM_SELF);
return;
}
server_supported_versions_ = packet.versions;
if (!SelectMutualVersion(packet.versions)) {
CloseConnection(
QUIC_INVALID_VERSION,
QuicStrCat(
"No common version found. Supported versions: {",
QuicTransportVersionVectorToString(framer_.supported_versions()),
"}, peer supported versions: {",
QuicTransportVersionVectorToString(packet.versions), "}"),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Negotiated version: "
<< QuicVersionToString(transport_version());
version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
RetransmitUnackedPackets(ALL_UNACKED_RETRANSMISSION);
}
bool QuicConnection::OnUnauthenticatedPublicHeader(
const QuicPacketPublicHeader& header) {
if (header.connection_id == connection_id_) {
return true;
}
++stats_.packets_dropped;
QUIC_DLOG(INFO) << ENDPOINT
<< "Ignoring packet from unexpected ConnectionId: "
<< header.connection_id << " instead of " << connection_id_;
if (debug_visitor_ != nullptr) {
debug_visitor_->OnIncorrectConnectionId(header.connection_id);
}
// If this is a server, the dispatcher routes each packet to the
// QuicConnection responsible for the packet's connection ID. So if control
// arrives here and this is a server, the dispatcher must be malfunctioning.
DCHECK_NE(Perspective::IS_SERVER, perspective_);
return false;
}
bool QuicConnection::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnUnauthenticatedHeader(header);
}
// Check that any public reset packet with a different connection ID that was
// routed to this QuicConnection has been redirected before control reaches
// here.
DCHECK_EQ(connection_id_, header.public_header.connection_id);
if (!packet_generator_.IsPendingPacketEmpty()) {
// Incoming packets may change a queued ACK frame.
const string error_details =
"Pending frames must be serialized before incoming packets are "
"processed.";
QUIC_BUG << error_details;
CloseConnection(QUIC_INTERNAL_ERROR, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
// If this packet has already been seen, or the sender has told us that it
// will not be retransmitted, then stop processing the packet.
if (!received_packet_manager_.IsAwaitingPacket(header.packet_number)) {
QUIC_DLOG(INFO) << ENDPOINT << "Packet " << header.packet_number
<< " no longer being waited for. Discarding.";
if (debug_visitor_ != nullptr) {
debug_visitor_->OnDuplicatePacket(header.packet_number);
}
++stats_.packets_dropped;
return false;
}
return true;
}
void QuicConnection::OnDecryptedPacket(EncryptionLevel level) {
last_decrypted_packet_level_ = level;
last_packet_decrypted_ = true;
// Once the server receives a forward secure packet, the handshake is
// confirmed.
if (level == ENCRYPTION_FORWARD_SECURE &&
perspective_ == Perspective::IS_SERVER) {
sent_packet_manager_.SetHandshakeConfirmed();
}
}
bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketHeader(header);
}
// Will be decremented below if we fall through to return true.
++stats_.packets_dropped;
if (!ProcessValidatedPacket(header)) {
return false;
}
PeerAddressChangeType peer_migration_type =
QuicUtils::DetermineAddressChangeType(peer_address_,
last_packet_source_address_);
// Initiate connection migration if a non-reordered packet is received from a
// new address.
if (header.packet_number > received_packet_manager_.GetLargestObserved() &&
peer_migration_type != NO_CHANGE) {
if (perspective_ == Perspective::IS_CLIENT) {
QUIC_DLOG(INFO) << ENDPOINT << "Peer's ip:port changed from "
<< peer_address_.ToString() << " to "
<< last_packet_source_address_.ToString();
peer_address_ = last_packet_source_address_;
} else if (active_peer_migration_type_ == NO_CHANGE) {
// Only migrate connection to a new peer address if there is no
// pending change underway.
StartPeerMigration(peer_migration_type);
}
}
--stats_.packets_dropped;
QUIC_DVLOG(1) << ENDPOINT << "Received packet header: " << header;
last_header_ = header;
// An ack will be sent if a missing retransmittable packet was received;
was_last_packet_missing_ =
received_packet_manager_.IsMissing(last_header_.packet_number);
// Record packet receipt to populate ack info before processing stream
// frames, since the processing may result in sending a bundled ack.
received_packet_manager_.RecordPacketReceived(last_header_,
time_of_last_received_packet_);
DCHECK(connected_);
return true;
}
bool QuicConnection::OnStreamFrame(const QuicStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStreamFrame(frame);
}
if (frame.stream_id != kCryptoStreamId &&
last_decrypted_packet_level_ == ENCRYPTION_NONE) {
if (MaybeConsiderAsMemoryCorruption(frame)) {
CloseConnection(QUIC_MAYBE_CORRUPTED_MEMORY,
"Received crypto frame on non crypto stream.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
QUIC_BUG << ENDPOINT
<< "Received an unencrypted data frame: closing connection"
<< " packet_number:" << last_header_.packet_number
<< " stream_id:" << frame.stream_id
<< " received_packets:" << received_packet_manager_.ack_frame();
CloseConnection(QUIC_UNENCRYPTED_STREAM_DATA,
"Unencrypted stream data seen.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
visitor_->OnStreamFrame(frame);
visitor_->PostProcessAfterData();
stats_.stream_bytes_received += frame.data_length;
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnAckFrame(const QuicAckFrame& incoming_ack) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnAckFrame(incoming_ack);
}
QUIC_DVLOG(1) << ENDPOINT << "OnAckFrame: " << incoming_ack;
if (last_header_.packet_number <= largest_seen_packet_with_ack_) {
QUIC_DLOG(INFO) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
const char* error = ValidateAckFrame(incoming_ack);
if (error != nullptr) {
CloseConnection(QUIC_INVALID_ACK_DATA, error,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
if (send_alarm_->IsSet()) {
send_alarm_->Cancel();
}
largest_seen_packet_with_ack_ = last_header_.packet_number;
sent_packet_manager_.OnIncomingAck(incoming_ack,
time_of_last_received_packet_);
if (no_stop_waiting_frames_) {
received_packet_manager_.DontWaitForPacketsBefore(
sent_packet_manager_.largest_packet_peer_knows_is_acked());
}
// Always reset the retransmission alarm when an ack comes in, since we now
// have a better estimate of the current rtt than when it was set.
SetRetransmissionAlarm();
// If the incoming ack's packets set expresses missing packets: peer is still
// waiting for a packet lower than a packet that we are no longer planning to
// send.
// If the incoming ack's packets set expresses received packets: peer is still
// acking packets which we never care about.
// Send an ack to raise the high water mark.
if (!incoming_ack.packets.Empty() &&
GetLeastUnacked() > incoming_ack.packets.Min()) {
++stop_waiting_count_;
} else {
stop_waiting_count_ = 0;
}
return connected_;
}
bool QuicConnection::OnStopWaitingFrame(const QuicStopWaitingFrame& frame) {
DCHECK(connected_);
if (no_stop_waiting_frames_) {
return true;
}
if (last_header_.packet_number <= largest_seen_packet_with_stop_waiting_) {
QUIC_DLOG(INFO) << ENDPOINT
<< "Received an old stop waiting frame: ignoring";
return true;
}
const char* error = ValidateStopWaitingFrame(frame);
if (error != nullptr) {
CloseConnection(QUIC_INVALID_STOP_WAITING_DATA, error,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStopWaitingFrame(frame);
}
largest_seen_packet_with_stop_waiting_ = last_header_.packet_number;
received_packet_manager_.DontWaitForPacketsBefore(frame.least_unacked);
return connected_;
}
bool QuicConnection::OnPaddingFrame(const QuicPaddingFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPaddingFrame(frame);
}
return true;
}
bool QuicConnection::OnPingFrame(const QuicPingFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPingFrame(frame);
}
should_last_packet_instigate_acks_ = true;
return true;
}
const char* QuicConnection::ValidateAckFrame(const QuicAckFrame& incoming_ack) {
if (incoming_ack.largest_observed > packet_generator_.packet_number()) {
QUIC_DLOG(WARNING) << ENDPOINT << "Peer's observed unsent packet:"
<< incoming_ack.largest_observed << " vs "
<< packet_generator_.packet_number();
// We got an error for data we have not sent. Error out.
return "Largest observed too high.";
}
if (incoming_ack.largest_observed <
sent_packet_manager_.GetLargestObserved()) {
QUIC_LOG(INFO) << ENDPOINT << "Peer's largest_observed packet decreased:"
<< incoming_ack.largest_observed << " vs "
<< sent_packet_manager_.GetLargestObserved()
<< " packet_number:" << last_header_.packet_number
<< " largest seen with ack:" << largest_seen_packet_with_ack_
<< " connection_id: " << connection_id_;
// A new ack has a diminished largest_observed value. Error out.
// If this was an old packet, we wouldn't even have checked.
return "Largest observed too low.";
}
if (!incoming_ack.packets.Empty() &&
incoming_ack.packets.Max() != incoming_ack.largest_observed) {
QUIC_BUG << ENDPOINT
<< "Peer last received packet: " << incoming_ack.packets.Max()
<< " which is not equal to largest observed: "
<< incoming_ack.largest_observed;
return "Last received packet not equal to largest observed.";
}
return nullptr;
}
const char* QuicConnection::ValidateStopWaitingFrame(
const QuicStopWaitingFrame& stop_waiting) {
if (stop_waiting.least_unacked <
received_packet_manager_.peer_least_packet_awaiting_ack()) {
QUIC_DLOG(ERROR)
<< ENDPOINT
<< "Peer's sent low least_unacked: " << stop_waiting.least_unacked
<< " vs " << received_packet_manager_.peer_least_packet_awaiting_ack();
// We never process old ack frames, so this number should only increase.
return "Least unacked too small.";
}
if (stop_waiting.least_unacked > last_header_.packet_number) {
QUIC_DLOG(ERROR) << ENDPOINT
<< "Peer sent least_unacked:" << stop_waiting.least_unacked
<< " greater than the enclosing packet number:"
<< last_header_.packet_number;
return "Least unacked too large.";
}
return nullptr;
}
bool QuicConnection::OnRstStreamFrame(const QuicRstStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRstStreamFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT
<< "RST_STREAM_FRAME received for stream: " << frame.stream_id
<< " with error: "
<< QuicRstStreamErrorCodeToString(frame.error_code);
visitor_->OnRstStream(frame);
visitor_->PostProcessAfterData();
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnConnectionCloseFrame(
const QuicConnectionCloseFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnConnectionCloseFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT << "Received ConnectionClose for connection: "
<< connection_id()
<< ", with error: " << QuicErrorCodeToString(frame.error_code)
<< " (" << frame.error_details << ")";
if (frame.error_code == QUIC_BAD_MULTIPATH_FLAG) {
QUIC_LOG_FIRST_N(ERROR, 10) << "Unexpected QUIC_BAD_MULTIPATH_FLAG error."
<< " last_received_header: " << last_header_
<< " encryption_level: " << encryption_level_;
}
TearDownLocalConnectionState(frame.error_code, frame.error_details,
ConnectionCloseSource::FROM_PEER);
return connected_;
}
bool QuicConnection::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnGoAwayFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT << "GOAWAY_FRAME received with last good stream: "
<< frame.last_good_stream_id
<< " and error: " << QuicErrorCodeToString(frame.error_code)
<< " and reason: " << frame.reason_phrase;
goaway_received_ = true;
visitor_->OnGoAway(frame);
visitor_->PostProcessAfterData();
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnWindowUpdateFrame(frame, time_of_last_received_packet_);
}
QUIC_DLOG(INFO) << ENDPOINT << "WINDOW_UPDATE_FRAME received for stream: "
<< frame.stream_id
<< " with byte offset: " << frame.byte_offset;
visitor_->OnWindowUpdateFrame(frame);
visitor_->PostProcessAfterData();
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnBlockedFrame(const QuicBlockedFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnBlockedFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT
<< "BLOCKED_FRAME received for stream: " << frame.stream_id;
visitor_->OnBlockedFrame(frame);
visitor_->PostProcessAfterData();
stats_.blocked_frames_received++;
should_last_packet_instigate_acks_ = true;
return connected_;
}
void QuicConnection::OnPacketComplete() {
// Don't do anything if this packet closed the connection.
if (!connected_) {
ClearLastFrames();
return;
}
QUIC_DVLOG(1) << ENDPOINT << "Got packet " << last_header_.packet_number
<< " for " << last_header_.public_header.connection_id;
// An ack will be sent if a missing retransmittable packet was received;
const bool was_missing =
should_last_packet_instigate_acks_ && was_last_packet_missing_;
// It's possible the ack frame was sent along with response data, so it
// no longer needs to be sent.
if (ack_frame_updated()) {
MaybeQueueAck(was_missing);
}
ClearLastFrames();
}
void QuicConnection::MaybeQueueAck(bool was_missing) {
++num_packets_received_since_last_ack_sent_;
// Always send an ack every 20 packets in order to allow the peer to discard
// information from the SentPacketManager and provide an RTT measurement.
if (transport_version() <= QUIC_VERSION_38 &&
num_packets_received_since_last_ack_sent_ >=
kMaxPacketsReceivedBeforeAckSend) {
ack_queued_ = true;
}
// Determine whether the newly received packet was missing before recording
// the received packet.
// Ack decimation with reordering relies on the timer to send an ack, but if
// missing packets we reported in the previous ack, send an ack immediately.
if (was_missing && (ack_mode_ != ACK_DECIMATION_WITH_REORDERING ||
last_ack_had_missing_packets_)) {
ack_queued_ = true;
}
if (should_last_packet_instigate_acks_ && !ack_queued_) {
++num_retransmittable_packets_received_since_last_ack_sent_;
if (ack_mode_ != TCP_ACKING &&
last_header_.packet_number > kMinReceivedBeforeAckDecimation) {
// Ack up to 10 packets at once unless ack decimation is unlimited.
if (!unlimited_ack_decimation_ &&
num_retransmittable_packets_received_since_last_ack_sent_ >=
kMaxRetransmittablePacketsBeforeAck) {
ack_queued_ = true;
} else if (!ack_alarm_->IsSet()) {
// Wait the minimum of a quarter min_rtt and the delayed ack time.
QuicTime::Delta ack_delay = std::min(
DelayedAckTime(), sent_packet_manager_.GetRttStats()->min_rtt() *
ack_decimation_delay_);
ack_alarm_->Set(clock_->ApproximateNow() + ack_delay);
}
} else {
// Ack with a timer or every 2 packets by default.
if (num_retransmittable_packets_received_since_last_ack_sent_ >=
kDefaultRetransmittablePacketsBeforeAck) {
ack_queued_ = true;
} else if (!ack_alarm_->IsSet()) {
ack_alarm_->Set(clock_->ApproximateNow() + DelayedAckTime());
}
}
// If there are new missing packets to report, send an ack immediately.
if (received_packet_manager_.HasNewMissingPackets()) {
if (ack_mode_ == ACK_DECIMATION_WITH_REORDERING) {
// Wait the minimum of an eighth min_rtt and the existing ack time.
QuicTime ack_time =
clock_->ApproximateNow() +
0.125 * sent_packet_manager_.GetRttStats()->min_rtt();
if (!ack_alarm_->IsSet() || ack_alarm_->deadline() > ack_time) {
ack_alarm_->Update(ack_time, QuicTime::Delta::Zero());
}
} else {
ack_queued_ = true;
}
}
}
if (ack_queued_) {
ack_alarm_->Cancel();
}
}
void QuicConnection::ClearLastFrames() {
should_last_packet_instigate_acks_ = false;
}
const QuicFrame QuicConnection::GetUpdatedAckFrame() {
return received_packet_manager_.GetUpdatedAckFrame(clock_->ApproximateNow());
}
void QuicConnection::PopulateStopWaitingFrame(
QuicStopWaitingFrame* stop_waiting) {
stop_waiting->least_unacked = GetLeastUnacked();
}
QuicPacketNumber QuicConnection::GetLeastUnacked() const {
return sent_packet_manager_.GetLeastUnacked();
}
void QuicConnection::MaybeSendInResponseToPacket() {
if (!connected_) {
return;
}
// Now that we have received an ack, we might be able to send packets which
// are queued locally, or drain streams which are blocked.
if (defer_send_in_response_to_packets_) {
send_alarm_->Update(clock_->ApproximateNow(), QuicTime::Delta::Zero());
} else {
WriteAndBundleAcksIfNotBlocked();
}
}
void QuicConnection::SendVersionNegotiationPacket() {
pending_version_negotiation_packet_ = true;
if (writer_->IsWriteBlocked()) {
visitor_->OnWriteBlocked();
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Sending version negotiation packet: {"
<< QuicTransportVersionVectorToString(
framer_.supported_versions())
<< "}";
std::unique_ptr<QuicEncryptedPacket> version_packet(
packet_generator_.SerializeVersionNegotiationPacket(
framer_.supported_versions()));
WriteResult result = writer_->WritePacket(
version_packet->data(), version_packet->length(), self_address().host(),
peer_address(), per_packet_options_);
if (result.status == WRITE_STATUS_ERROR) {
OnWriteError(result.error_code);
return;
}
if (result.status == WRITE_STATUS_BLOCKED) {
visitor_->OnWriteBlocked();
if (writer_->IsWriteBlockedDataBuffered()) {
pending_version_negotiation_packet_ = false;
}
return;
}
pending_version_negotiation_packet_ = false;
}
QuicConsumedData QuicConnection::SendStreamData(
QuicStreamId id,
QuicIOVector iov,
QuicStreamOffset offset,
StreamSendingState state,
QuicReferenceCountedPointer<QuicAckListenerInterface> ack_listener) {
if (state == NO_FIN && iov.total_length == 0) {
QUIC_BUG << "Attempt to send empty stream frame";
return QuicConsumedData(0, false);
}
// Opportunistically bundle an ack with every outgoing packet.
// Particularly, we want to bundle with handshake packets since we don't know
// which decrypter will be used on an ack packet following a handshake
// packet (a handshake packet from client to server could result in a REJ or a
// SHLO from the server, leading to two different decrypters at the server.)
ScopedRetransmissionScheduler alarm_delayer(this);
ScopedPacketBundler ack_bundler(this, SEND_ACK_IF_PENDING);
return packet_generator_.ConsumeData(id, iov, offset, state,
std::move(ack_listener));
}
void QuicConnection::SendRstStream(QuicStreamId id,
QuicRstStreamErrorCode error,
QuicStreamOffset bytes_written) {
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, SEND_ACK_IF_PENDING);
packet_generator_.AddControlFrame(
QuicFrame(new QuicRstStreamFrame(id, error, bytes_written)));
if (error == QUIC_STREAM_NO_ERROR) {
// All data for streams which are reset with QUIC_STREAM_NO_ERROR must
// be received by the peer.
return;
}
sent_packet_manager_.CancelRetransmissionsForStream(id);
// Remove all queued packets which only contain data for the reset stream.
QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
while (packet_iterator != queued_packets_.end()) {
QuicFrames* retransmittable_frames =
&packet_iterator->retransmittable_frames;
if (retransmittable_frames->empty()) {
++packet_iterator;
continue;
}
RemoveFramesForStream(retransmittable_frames, id);
if (!retransmittable_frames->empty()) {
++packet_iterator;
continue;
}
delete[] packet_iterator->encrypted_buffer;
ClearSerializedPacket(&(*packet_iterator));
packet_iterator = queued_packets_.erase(packet_iterator);
}
// TODO(ianswett): Consider checking for 3 RTOs when the last stream is
// cancelled as well.
}
void QuicConnection::SendWindowUpdate(QuicStreamId id,
QuicStreamOffset byte_offset) {
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, SEND_ACK_IF_PENDING);
packet_generator_.AddControlFrame(
QuicFrame(new QuicWindowUpdateFrame(id, byte_offset)));
}
void QuicConnection::SendBlocked(QuicStreamId id) {
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, SEND_ACK_IF_PENDING);
packet_generator_.AddControlFrame(QuicFrame(new QuicBlockedFrame(id)));
stats_.blocked_frames_sent++;
}
const QuicConnectionStats& QuicConnection::GetStats() {
const RttStats* rtt_stats = sent_packet_manager_.GetRttStats();
// Update rtt and estimated bandwidth.
QuicTime::Delta min_rtt = rtt_stats->min_rtt();
if (min_rtt.IsZero()) {
// If min RTT has not been set, use initial RTT instead.
min_rtt = QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us());
}
stats_.min_rtt_us = min_rtt.ToMicroseconds();
QuicTime::Delta srtt = rtt_stats->smoothed_rtt();
if (srtt.IsZero()) {
// If SRTT has not been set, use initial RTT instead.
srtt = QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us());
}
stats_.srtt_us = srtt.ToMicroseconds();
stats_.estimated_bandwidth = sent_packet_manager_.BandwidthEstimate();
stats_.max_packet_size = packet_generator_.GetCurrentMaxPacketLength();
stats_.max_received_packet_size = largest_received_packet_size_;
return stats_;
}
void QuicConnection::ProcessUdpPacket(const QuicSocketAddress& self_address,
const QuicSocketAddress& peer_address,
const QuicReceivedPacket& packet) {
if (!connected_) {
return;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
}
last_size_ = packet.length();
current_packet_data_ = packet.data();
last_packet_destination_address_ = self_address;
last_packet_source_address_ = peer_address;
if (!self_address_.IsInitialized()) {
self_address_ = last_packet_destination_address_;
}
if (!peer_address_.IsInitialized()) {
peer_address_ = last_packet_source_address_;
}
stats_.bytes_received += packet.length();
++stats_.packets_received;
// Ensure the time coming from the packet reader is within a minute of now.
if (std::abs((packet.receipt_time() - clock_->ApproximateNow()).ToSeconds()) >
60) {
QUIC_BUG << "Packet receipt time:"
<< packet.receipt_time().ToDebuggingValue()
<< " too far from current time:"
<< clock_->ApproximateNow().ToDebuggingValue();
}
time_of_last_received_packet_ = packet.receipt_time();
QUIC_DVLOG(1) << ENDPOINT << "time of last received packet: "
<< time_of_last_received_packet_.ToDebuggingValue();
ScopedRetransmissionScheduler alarm_delayer(this);
if (!framer_.ProcessPacket(packet)) {
// If we are unable to decrypt this packet, it might be
// because the CHLO or SHLO packet was lost.
if (framer_.error() == QUIC_DECRYPTION_FAILURE) {
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
undecryptable_packets_.size() < max_undecryptable_packets_) {
QueueUndecryptablePacket(packet);
} else if (debug_visitor_ != nullptr) {
debug_visitor_->OnUndecryptablePacket();
}
}
QUIC_DVLOG(1) << ENDPOINT
<< "Unable to process packet. Last packet processed: "
<< last_header_.packet_number;
current_packet_data_ = nullptr;
return;
}
++stats_.packets_processed;
if (active_peer_migration_type_ != NO_CHANGE &&
sent_packet_manager_.GetLargestObserved() >
highest_packet_sent_before_peer_migration_) {
if (perspective_ == Perspective::IS_SERVER) {
OnPeerMigrationValidated();
}
}
MaybeProcessUndecryptablePackets();
MaybeSendInResponseToPacket();
SetPingAlarm();
current_packet_data_ = nullptr;
}
void QuicConnection::OnBlockedWriterCanWrite() {
OnCanWrite();
}
void QuicConnection::OnCanWrite() {
DCHECK(!writer_->IsWriteBlocked());
WriteQueuedPackets();
WritePendingRetransmissions();
// Sending queued packets may have caused the socket to become write blocked,
// or the congestion manager to prohibit sending. If we've sent everything
// we had queued and we're still not blocked, let the visitor know it can
// write more.
if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
return;
}
{
ScopedPacketBundler bundler(this, SEND_ACK_IF_QUEUED);
visitor_->OnCanWrite();
visitor_->PostProcessAfterData();
}
// After the visitor writes, it may have caused the socket to become write
// blocked or the congestion manager to prohibit sending, so check again.
if (visitor_->WillingAndAbleToWrite() && !resume_writes_alarm_->IsSet() &&
CanWrite(HAS_RETRANSMITTABLE_DATA)) {
// We're not write blocked, but some stream didn't write out all of its
// bytes. Register for 'immediate' resumption so we'll keep writing after
// other connections and events have had a chance to use the thread.
resume_writes_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::WriteIfNotBlocked() {
if (!writer_->IsWriteBlocked()) {
OnCanWrite();
}
}
void QuicConnection::WriteAndBundleAcksIfNotBlocked() {
if (!writer_->IsWriteBlocked()) {
ScopedPacketBundler bundler(this, SEND_ACK_IF_QUEUED);
OnCanWrite();
}
}
bool QuicConnection::ProcessValidatedPacket(const QuicPacketHeader& header) {
if (perspective_ == Perspective::IS_SERVER && self_address_.IsInitialized() &&
last_packet_destination_address_.IsInitialized() &&
self_address_ != last_packet_destination_address_) {
// Allow change between pure IPv4 and equivalent mapped IPv4 address.
if (self_address_.port() != last_packet_destination_address_.port() ||
self_address_.host().Normalized() !=
last_packet_destination_address_.host().Normalized()) {
if (FLAGS_quic_reloadable_flag_quic_allow_one_address_change &&
AllowSelfAddressChange()) {
QUIC_FLAG_COUNT_N(quic_reloadable_flag_quic_allow_one_address_change, 2,
2);
OnSelfAddressChange();
} else {
CloseConnection(
QUIC_ERROR_MIGRATING_ADDRESS,
"Self address migration is not supported at the server.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
}
self_address_ = last_packet_destination_address_;
}
if (FLAGS_quic_restart_flag_quic_enable_accept_random_ipn) {
QUIC_FLAG_COUNT_N(quic_restart_flag_quic_enable_accept_random_ipn, 2, 2);
// Configured to accept any packet number in range 1...0x7fffffff
// as initial packet number.
if (last_header_.packet_number != 0) {
// The last packet's number is not 0. Ensure that this packet
// is reasonably close to where it should be.
if (!Near(header.packet_number, last_header_.packet_number)) {
QUIC_DLOG(INFO) << ENDPOINT << "Packet " << header.packet_number
<< " out of bounds. Discarding";
CloseConnection(QUIC_INVALID_PACKET_HEADER,
"Packet number out of bounds.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
} else {
// The "last packet's number" is 0, meaning that this packet is the first
// one received. Ensure it is in range 1..kMaxRandomInitialPacketNumber,
// inclusive.
if ((header.packet_number == 0) ||
(header.packet_number > kMaxRandomInitialPacketNumber)) {
// packet number is bad.
QUIC_DLOG(INFO) << ENDPOINT << "Initial packet " << header.packet_number
<< " out of bounds. Discarding";
CloseConnection(QUIC_INVALID_PACKET_HEADER,
"Initial packet number out of bounds.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
}
} else { // if (FLAGS_quic_reloadable_flag_quic_accept_random_ipn) {
// Count those that would have been accepted if FLAGS..random_ipn
// were true -- to detect/diagnose potential issues prior to
// enabling the flag.
if ((header.packet_number > 1) &&
(header.packet_number <= kMaxRandomInitialPacketNumber)) {
QUIC_CODE_COUNT_N(had_possibly_random_ipn, 2, 2);
}
if (!Near(header.packet_number, last_header_.packet_number)) {
QUIC_DLOG(INFO) << ENDPOINT << "Packet " << header.packet_number
<< " out of bounds. Discarding";
CloseConnection(QUIC_INVALID_PACKET_HEADER,
"Packet number out of bounds.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
}
if (version_negotiation_state_ != NEGOTIATED_VERSION) {
if (perspective_ == Perspective::IS_SERVER) {
if (!header.public_header.version_flag) {
// Packets should have the version flag till version negotiation is
// done.
string error_details =
QuicStrCat(ENDPOINT, "Packet ", header.packet_number,
" without version flag before version negotiated.");
QUIC_DLOG(WARNING) << error_details;
CloseConnection(QUIC_INVALID_VERSION, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
} else {
DCHECK_EQ(1u, header.public_header.versions.size());
DCHECK_EQ(header.public_header.versions[0], transport_version());
version_negotiation_state_ = NEGOTIATED_VERSION;
visitor_->OnSuccessfulVersionNegotiation(transport_version());
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(transport_version());
}
}
} else {
DCHECK(!header.public_header.version_flag);
// If the client gets a packet without the version flag from the server
// it should stop sending version since the version negotiation is done.
packet_generator_.StopSendingVersion();
version_negotiation_state_ = NEGOTIATED_VERSION;
visitor_->OnSuccessfulVersionNegotiation(transport_version());
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(transport_version());
}
}
}
DCHECK_EQ(NEGOTIATED_VERSION, version_negotiation_state_);
if (last_size_ > largest_received_packet_size_) {
largest_received_packet_size_ = last_size_;
}
if (perspective_ == Perspective::IS_SERVER &&
encryption_level_ == ENCRYPTION_NONE &&
last_size_ > packet_generator_.GetCurrentMaxPacketLength()) {
SetMaxPacketLength(last_size_);
}
return true;
}
void QuicConnection::WriteQueuedPackets() {
DCHECK(!writer_->IsWriteBlocked());
if (pending_version_negotiation_packet_) {
SendVersionNegotiationPacket();
}
QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
while (packet_iterator != queued_packets_.end() &&
WritePacket(&(*packet_iterator))) {
delete[] packet_iterator->encrypted_buffer;
ClearSerializedPacket(&(*packet_iterator));
packet_iterator = queued_packets_.erase(packet_iterator);
}
}
void QuicConnection::WritePendingRetransmissions() {
// Keep writing as long as there's a pending retransmission which can be
// written.
while (sent_packet_manager_.HasPendingRetransmissions()) {
const QuicPendingRetransmission pending =
sent_packet_manager_.NextPendingRetransmission();
if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
break;
}
// Re-packetize the frames with a new packet number for retransmission.
// Retransmitted packets use the same packet number length as the
// original.
// Flush the packet generator before making a new packet.
// TODO(ianswett): Implement ReserializeAllFrames as a separate path that
// does not require the creator to be flushed.
packet_generator_.FlushAllQueuedFrames();
char buffer[kMaxPacketSize];
packet_generator_.ReserializeAllFrames(pending, buffer, kMaxPacketSize);
}
}
void QuicConnection::RetransmitUnackedPackets(
TransmissionType retransmission_type) {
sent_packet_manager_.RetransmitUnackedPackets(retransmission_type);
WriteIfNotBlocked();
}
void QuicConnection::NeuterUnencryptedPackets() {
sent_packet_manager_.NeuterUnencryptedPackets();
// This may have changed the retransmission timer, so re-arm it.
SetRetransmissionAlarm();
}
bool QuicConnection::ShouldGeneratePacket(
HasRetransmittableData retransmittable,
IsHandshake handshake) {
// We should serialize handshake packets immediately to ensure that they
// end up sent at the right encryption level.
if (handshake == IS_HANDSHAKE) {
return true;
}
return CanWrite(retransmittable);
}
bool QuicConnection::CanWrite(HasRetransmittableData retransmittable) {
if (!connected_) {
return false;
}
if (writer_->IsWriteBlocked()) {
visitor_->OnWriteBlocked();
return false;
}
// Allow acks to be sent immediately.
if (retransmittable == NO_RETRANSMITTABLE_DATA) {
return true;
}
// If the send alarm is set, wait for it to fire.
if (send_alarm_->IsSet()) {
return false;
}
QuicTime now = clock_->Now();
QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(now);
if (delay.IsInfinite()) {
send_alarm_->Cancel();
return false;
}
// If the scheduler requires a delay, then we can not send this packet now.
if (!delay.IsZero()) {
send_alarm_->Update(now + delay, QuicTime::Delta::FromMilliseconds(1));
QUIC_DVLOG(1) << ENDPOINT << "Delaying sending " << delay.ToMilliseconds()
<< "ms";
return false;
}
return true;
}
bool QuicConnection::WritePacket(SerializedPacket* packet) {
if (packet->packet_number < sent_packet_manager_.GetLargestSentPacket()) {
QUIC_BUG << "Attempt to write packet:" << packet->packet_number
<< " after:" << sent_packet_manager_.GetLargestSentPacket();
CloseConnection(QUIC_INTERNAL_ERROR, "Packet written out of order.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return true;
}
if (ShouldDiscardPacket(*packet)) {
++stats_.packets_discarded;
return true;
}
// Termination packets are encrypted and saved, so don't exit early.
const bool is_termination_packet = IsTerminationPacket(*packet);
if (writer_->IsWriteBlocked() && !is_termination_packet) {
return false;
}
QuicPacketNumber packet_number = packet->packet_number;
QuicPacketLength encrypted_length = packet->encrypted_length;
// Termination packets are eventually owned by TimeWaitListManager.
// Others are deleted at the end of this call.
if (is_termination_packet) {
if (termination_packets_ == nullptr) {
termination_packets_.reset(
new std::vector<std::unique_ptr<QuicEncryptedPacket>>);
}
// Copy the buffer so it's owned in the future.
char* buffer_copy = CopyBuffer(*packet);
termination_packets_->push_back(std::unique_ptr<QuicEncryptedPacket>(
new QuicEncryptedPacket(buffer_copy, encrypted_length, true)));
// This assures we won't try to write *forced* packets when blocked.
// Return true to stop processing.
if (writer_->IsWriteBlocked()) {
visitor_->OnWriteBlocked();
return true;
}
}
DCHECK_LE(encrypted_length, kMaxPacketSize);
DCHECK_LE(encrypted_length, packet_generator_.GetCurrentMaxPacketLength());
QUIC_DVLOG(1) << ENDPOINT << "Sending packet " << packet_number << " : "
<< (IsRetransmittable(*packet) == HAS_RETRANSMITTABLE_DATA
? "data bearing "
: " ack only ")
<< ", encryption level: "
<< QuicUtils::EncryptionLevelToString(packet->encryption_level)
<< ", encrypted length:" << encrypted_length;
QUIC_DVLOG(2) << ENDPOINT << "packet(" << packet_number << "): " << std::endl
<< QuicTextUtils::HexDump(QuicStringPiece(
packet->encrypted_buffer, encrypted_length));
// Measure the RTT from before the write begins to avoid underestimating the
// min_rtt_, especially in cases where the thread blocks or gets swapped out
// during the WritePacket below.
QuicTime packet_send_time = clock_->Now();
WriteResult result = writer_->WritePacket(
packet->encrypted_buffer, encrypted_length, self_address().host(),
peer_address(), per_packet_options_);
if (result.error_code == ERR_IO_PENDING) {
DCHECK_EQ(WRITE_STATUS_BLOCKED, result.status);
}
if (result.status == WRITE_STATUS_BLOCKED) {
visitor_->OnWriteBlocked();
// If the socket buffers the data, then the packet should not
// be queued and sent again, which would result in an unnecessary
// duplicate packet being sent. The helper must call OnCanWrite
// when the write completes, and OnWriteError if an error occurs.
if (!writer_->IsWriteBlockedDataBuffered()) {
return false;
}
}
// In some cases, an MTU probe can cause EMSGSIZE. This indicates that the
// MTU discovery is permanently unsuccessful.
if (result.status == WRITE_STATUS_ERROR &&
result.error_code == kMessageTooBigErrorCode &&
packet->retransmittable_frames.empty() &&
packet->encrypted_length > long_term_mtu_) {
mtu_discovery_target_ = 0;
mtu_discovery_alarm_->Cancel();
// The write failed, but the writer is not blocked, so return true.
return true;
}
if (result.status == WRITE_STATUS_ERROR) {
OnWriteError(result.error_code);
QUIC_LOG_FIRST_N(ERROR, 10)
<< ENDPOINT << "failed writing " << encrypted_length
<< " bytes from host " << self_address().host().ToString()
<< " to address " << peer_address().ToString() << " with error code "
<< result.error_code;
return false;
}
if (result.status != WRITE_STATUS_ERROR && debug_visitor_ != nullptr) {
// Pass the write result to the visitor.
debug_visitor_->OnPacketSent(*packet, packet->original_packet_number,
packet->transmission_type, packet_send_time);
}
if (packet->transmission_type == NOT_RETRANSMISSION) {
time_of_last_sent_new_packet_ = packet_send_time;
}
// Only adjust the last sent time (for the purpose of tracking the idle
// timeout) if this is the first retransmittable packet sent after a
// packet is received. If it were updated on every sent packet, then
// sending into a black hole might never timeout.
if (IsRetransmittable(*packet) == HAS_RETRANSMITTABLE_DATA &&
last_send_for_timeout_ <= time_of_last_received_packet_) {
last_send_for_timeout_ = packet_send_time;
}
SetPingAlarm();
MaybeSetMtuAlarm(packet_number);
QUIC_DVLOG(1) << ENDPOINT << "time we began writing last sent packet: "
<< packet_send_time.ToDebuggingValue();
bool reset_retransmission_alarm = sent_packet_manager_.OnPacketSent(
packet, packet->original_packet_number, packet_send_time,
packet->transmission_type, IsRetransmittable(*packet));
if (reset_retransmission_alarm || !retransmission_alarm_->IsSet()) {
SetRetransmissionAlarm();
}
// The packet number length must be updated after OnPacketSent, because it
// may change the packet number length in packet.
packet_generator_.UpdateSequenceNumberLength(
sent_packet_manager_.GetLeastUnacked(),
sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
stats_.bytes_sent += result.bytes_written;
++stats_.packets_sent;
if (packet->transmission_type != NOT_RETRANSMISSION) {
stats_.bytes_retransmitted += result.bytes_written;
++stats_.packets_retransmitted;
}
return true;
}
bool QuicConnection::ShouldDiscardPacket(const SerializedPacket& packet) {
if (!connected_) {
QUIC_DLOG(INFO) << ENDPOINT
<< "Not sending packet as connection is disconnected.";
return true;
}
QuicPacketNumber packet_number = packet.packet_number;
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE &&
packet.encryption_level == ENCRYPTION_NONE) {
// Drop packets that are NULL encrypted since the peer won't accept them
// anymore.
QUIC_DLOG(INFO) << ENDPOINT
<< "Dropping NULL encrypted packet: " << packet_number
<< " since the connection is forward secure.";
return true;
}
return false;
}
bool QuicConnection::AllowSelfAddressChange() const {
return false;
}
void QuicConnection::OnWriteError(int error_code) {
if (write_error_occurred_) {
// A write error already occurred. The connection is being closed.
return;
}
write_error_occurred_ = true;
const string error_details = QuicStrCat(
"Write failed with error: ", error_code, " (", strerror(error_code), ")");
QUIC_LOG_FIRST_N(ERROR, 2) << ENDPOINT << error_details;
switch (error_code) {
case kMessageTooBigErrorCode:
CloseConnection(
QUIC_PACKET_WRITE_ERROR, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK);
break;
default:
// We can't send an error as the socket is presumably borked.
TearDownLocalConnectionState(QUIC_PACKET_WRITE_ERROR, error_details,
ConnectionCloseSource::FROM_SELF);
}
}
void QuicConnection::OnSerializedPacket(SerializedPacket* serialized_packet) {
if (serialized_packet->encrypted_buffer == nullptr) {
// We failed to serialize the packet, so close the connection.
// TearDownLocalConnectionState does not send close packet, so no infinite
// loop here.
// TODO(ianswett): This is actually an internal error, not an
// encryption failure.
TearDownLocalConnectionState(
QUIC_ENCRYPTION_FAILURE,
"Serialized packet does not have an encrypted buffer.",
ConnectionCloseSource::FROM_SELF);
return;
}
if (transport_version() > QUIC_VERSION_38) {
if (serialized_packet->retransmittable_frames.empty() &&
serialized_packet->original_packet_number == 0) {
// Increment consecutive_num_packets_with_no_retransmittable_frames_ if
// this packet is a new transmission with no retransmittable frames.
++consecutive_num_packets_with_no_retransmittable_frames_;
} else {
consecutive_num_packets_with_no_retransmittable_frames_ = 0;
}
}
SendOrQueuePacket(serialized_packet);
}
void QuicConnection::OnUnrecoverableError(QuicErrorCode error,
const string& error_details,
ConnectionCloseSource source) {
// The packet creator or generator encountered an unrecoverable error: tear
// down local connection state immediately.
TearDownLocalConnectionState(error, error_details, source);
}
void QuicConnection::OnCongestionChange() {
visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
// Uses the connection's smoothed RTT. If zero, uses initial_rtt.
QuicTime::Delta rtt = sent_packet_manager_.GetRttStats()->smoothed_rtt();
if (rtt.IsZero()) {
rtt = QuicTime::Delta::FromMicroseconds(
sent_packet_manager_.GetRttStats()->initial_rtt_us());
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRttChanged(rtt);
}
}
void QuicConnection::OnPathDegrading() {
visitor_->OnPathDegrading();
}
void QuicConnection::OnPathMtuIncreased(QuicPacketLength packet_size) {
if (packet_size > max_packet_length()) {
SetMaxPacketLength(packet_size);
}
}
void QuicConnection::OnHandshakeComplete() {
sent_packet_manager_.SetHandshakeConfirmed();
// The client should immediately ack the SHLO to confirm the handshake is
// complete with the server.
if (perspective_ == Perspective::IS_CLIENT && !ack_queued_ &&
ack_frame_updated()) {
ack_alarm_->Update(clock_->ApproximateNow(), QuicTime::Delta::Zero());
}
}
void QuicConnection::SendOrQueuePacket(SerializedPacket* packet) {
// The caller of this function is responsible for checking CanWrite().
if (packet->encrypted_buffer == nullptr) {
QUIC_BUG << "packet.encrypted_buffer == nullptr in to SendOrQueuePacket";
return;
}
// If there are already queued packets, queue this one immediately to ensure
// it's written in sequence number order.
if (!queued_packets_.empty() || !WritePacket(packet)) {
// Take ownership of the underlying encrypted packet.
packet->encrypted_buffer = CopyBuffer(*packet);
queued_packets_.push_back(*packet);
packet->retransmittable_frames.clear();
}
ClearSerializedPacket(packet);
}
void QuicConnection::OnPingTimeout() {
if (!retransmission_alarm_->IsSet()) {
SendPing();
}
}
void QuicConnection::SendPing() {
ScopedPacketBundler bundler(this, SEND_ACK_IF_QUEUED);
packet_generator_.AddControlFrame(QuicFrame(QuicPingFrame()));
// Send PING frame immediately, without checking for congestion window bounds.
packet_generator_.FlushAllQueuedFrames();
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPingSent();
}
}
void QuicConnection::SendAck() {
ack_alarm_->Cancel();
ack_queued_ = false;
stop_waiting_count_ = 0;
num_retransmittable_packets_received_since_last_ack_sent_ = 0;
last_ack_had_missing_packets_ = received_packet_manager_.HasMissingPackets();
num_packets_received_since_last_ack_sent_ = 0;
packet_generator_.SetShouldSendAck(!no_stop_waiting_frames_);
if (consecutive_num_packets_with_no_retransmittable_frames_ <
kMaxConsecutiveNonRetransmittablePackets) {
return;
}
consecutive_num_packets_with_no_retransmittable_frames_ = 0;
if (packet_generator_.HasRetransmittableFrames()) {
// There is pending retransmittable frames.
return;
}
visitor_->OnAckNeedsRetransmittableFrame();
if (!packet_generator_.HasRetransmittableFrames()) {
// Visitor did not add a retransmittable frame, add a ping frame.
packet_generator_.AddControlFrame(QuicFrame(QuicPingFrame()));
}
}
void QuicConnection::OnRetransmissionTimeout() {
DCHECK(sent_packet_manager_.HasUnackedPackets());
if (close_connection_after_three_rtos_ &&
sent_packet_manager_.GetConsecutiveRtoCount() >= 2 &&
!visitor_->HasOpenDynamicStreams()) {
// Close on the 3rd consecutive RTO, so after 2 previous RTOs have occurred.
CloseConnection(QUIC_TOO_MANY_RTOS, "3 consecutive retransmission timeouts",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (close_connection_after_five_rtos_ &&
sent_packet_manager_.GetConsecutiveRtoCount() >= 4) {
// Close on the 5th consecutive RTO, so after 4 previous RTOs have occurred.
CloseConnection(QUIC_TOO_MANY_RTOS, "5 consecutive retransmission timeouts",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
sent_packet_manager_.OnRetransmissionTimeout();
WriteIfNotBlocked();
// A write failure can result in the connection being closed, don't attempt to
// write further packets, or to set alarms.
if (!connected_) {
return;
}
// In the TLP case, the SentPacketManager gives the connection the opportunity
// to send new data before retransmitting.
if (sent_packet_manager_.MaybeRetransmitTailLossProbe()) {
// Send the pending retransmission now that it's been queued.
WriteIfNotBlocked();
}
// Ensure the retransmission alarm is always set if there are unacked packets
// and nothing waiting to be sent.
// This happens if the loss algorithm invokes a timer based loss, but the
// packet doesn't need to be retransmitted.
if (!HasQueuedData() && !retransmission_alarm_->IsSet()) {
SetRetransmissionAlarm();
}
}
void QuicConnection::SetEncrypter(EncryptionLevel level,
QuicEncrypter* encrypter) {
packet_generator_.SetEncrypter(level, encrypter);
}
void QuicConnection::SetDiversificationNonce(
const DiversificationNonce& nonce) {
DCHECK_EQ(Perspective::IS_SERVER, perspective_);
packet_generator_.SetDiversificationNonce(nonce);
}
void QuicConnection::SetDefaultEncryptionLevel(EncryptionLevel level) {
encryption_level_ = level;
packet_generator_.set_encryption_level(level);
}
void QuicConnection::SetDecrypter(EncryptionLevel level,
QuicDecrypter* decrypter) {
framer_.SetDecrypter(level, decrypter);
}
void QuicConnection::SetAlternativeDecrypter(EncryptionLevel level,
QuicDecrypter* decrypter,
bool latch_once_used) {
framer_.SetAlternativeDecrypter(level, decrypter, latch_once_used);
}
const QuicDecrypter* QuicConnection::decrypter() const {
return framer_.decrypter();
}
const QuicDecrypter* QuicConnection::alternative_decrypter() const {
return framer_.alternative_decrypter();
}
void QuicConnection::QueueUndecryptablePacket(
const QuicEncryptedPacket& packet) {
QUIC_DVLOG(1) << ENDPOINT << "Queueing undecryptable packet.";
undecryptable_packets_.push_back(packet.Clone());
}
void QuicConnection::MaybeProcessUndecryptablePackets() {
if (undecryptable_packets_.empty() || encryption_level_ == ENCRYPTION_NONE) {
return;
}
while (connected_ && !undecryptable_packets_.empty()) {
QUIC_DVLOG(1) << ENDPOINT << "Attempting to process undecryptable packet";
QuicEncryptedPacket* packet = undecryptable_packets_.front().get();
if (!framer_.ProcessPacket(*packet) &&
framer_.error() == QUIC_DECRYPTION_FAILURE) {
QUIC_DVLOG(1) << ENDPOINT << "Unable to process undecryptable packet...";
break;
}
QUIC_DVLOG(1) << ENDPOINT << "Processed undecryptable packet!";
++stats_.packets_processed;
undecryptable_packets_.pop_front();
}
// Once forward secure encryption is in use, there will be no
// new keys installed and hence any undecryptable packets will
// never be able to be decrypted.
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE) {
if (debug_visitor_ != nullptr) {
// TODO(rtenneti): perhaps more efficient to pass the number of
// undecryptable packets as the argument to OnUndecryptablePacket so that
// we just need to call OnUndecryptablePacket once?
for (size_t i = 0; i < undecryptable_packets_.size(); ++i) {
debug_visitor_->OnUndecryptablePacket();
}
}
undecryptable_packets_.clear();
}
}
void QuicConnection::CloseConnection(
QuicErrorCode error,
const string& error_details,
ConnectionCloseBehavior connection_close_behavior) {
DCHECK(!error_details.empty());
if (!connected_) {
QUIC_DLOG(INFO) << "Connection is already closed.";
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Closing connection: " << connection_id()
<< ", with error: " << QuicErrorCodeToString(error) << " ("
<< error << "), and details: " << error_details;
if (connection_close_behavior ==
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET) {
SendConnectionClosePacket(error, error_details, SEND_ACK);
} else if (connection_close_behavior ==
ConnectionCloseBehavior::
SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK) {
SendConnectionClosePacket(error, error_details, NO_ACK);
}
ConnectionCloseSource source = ConnectionCloseSource::FROM_SELF;
if (perspective_ == Perspective::IS_CLIENT &&
error == QUIC_CRYPTO_HANDSHAKE_STATELESS_REJECT) {
// Regard stateless rejected connection as closed by server.
source = ConnectionCloseSource::FROM_PEER;
}
TearDownLocalConnectionState(error, error_details, source);
}
void QuicConnection::SendConnectionClosePacket(QuicErrorCode error,
const string& details,
AckBundling ack_mode) {
QUIC_DLOG(INFO) << ENDPOINT << "Sending connection close packet.";
ClearQueuedPackets();
ScopedPacketBundler ack_bundler(this, ack_mode);
QuicConnectionCloseFrame* frame = new QuicConnectionCloseFrame();
frame->error_code = error;
frame->error_details = details;
packet_generator_.AddControlFrame(QuicFrame(frame));
packet_generator_.FlushAllQueuedFrames();
}
void QuicConnection::TearDownLocalConnectionState(
QuicErrorCode error,
const string& error_details,
ConnectionCloseSource source) {
if (!connected_) {
QUIC_DLOG(INFO) << "Connection is already closed.";
return;
}
connected_ = false;
DCHECK(visitor_ != nullptr);
// TODO(rtenneti): crbug.com/546668. A temporary fix. Added a check for null
// |visitor_| to fix crash bug. Delete |visitor_| check and histogram after
// fix is merged.
if (visitor_ != nullptr) {
visitor_->OnConnectionClosed(error, error_details, source);
} else {
UMA_HISTOGRAM_BOOLEAN("Net.QuicCloseConnection.NullVisitor", true);
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnConnectionClosed(error, error_details, source);
}
// Cancel the alarms so they don't trigger any action now that the
// connection is closed.
CancelAllAlarms();
}
void QuicConnection::CancelAllAlarms() {
QUIC_DVLOG(1) << "Cancelling all QuicConnection alarms.";
ack_alarm_->Cancel();
ping_alarm_->Cancel();
resume_writes_alarm_->Cancel();
retransmission_alarm_->Cancel();
send_alarm_->Cancel();
timeout_alarm_->Cancel();
mtu_discovery_alarm_->Cancel();
}
void QuicConnection::SendGoAway(QuicErrorCode error,
QuicStreamId last_good_stream_id,
const string& reason) {
if (goaway_sent_) {
return;
}
goaway_sent_ = true;
QUIC_DLOG(INFO) << ENDPOINT << "Going away with error "
<< QuicErrorCodeToString(error) << " (" << error << ")";
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, SEND_ACK_IF_PENDING);
packet_generator_.AddControlFrame(
QuicFrame(new QuicGoAwayFrame(error, last_good_stream_id, reason)));
}
QuicByteCount QuicConnection::max_packet_length() const {
return packet_generator_.GetCurrentMaxPacketLength();
}
void QuicConnection::SetMaxPacketLength(QuicByteCount length) {
long_term_mtu_ = length;
packet_generator_.SetMaxPacketLength(GetLimitedMaxPacketSize(length));
}
bool QuicConnection::HasQueuedData() const {
return pending_version_negotiation_packet_ || !queued_packets_.empty() ||
packet_generator_.HasQueuedFrames();
}
void QuicConnection::EnableSavingCryptoPackets() {
save_crypto_packets_as_termination_packets_ = true;
}
bool QuicConnection::CanWriteStreamData() {
// Don't write stream data if there are negotiation or queued data packets
// to send. Otherwise, continue and bundle as many frames as possible.
if (pending_version_negotiation_packet_ || !queued_packets_.empty()) {
return false;
}
IsHandshake pending_handshake =
visitor_->HasPendingHandshake() ? IS_HANDSHAKE : NOT_HANDSHAKE;
// Sending queued packets may have caused the socket to become write blocked,
// or the congestion manager to prohibit sending. If we've sent everything
// we had queued and we're still not blocked, let the visitor know it can
// write more.
return ShouldGeneratePacket(HAS_RETRANSMITTABLE_DATA, pending_handshake);
}
void QuicConnection::SetNetworkTimeouts(QuicTime::Delta handshake_timeout,
QuicTime::Delta idle_timeout) {
QUIC_BUG_IF(idle_timeout > handshake_timeout)
<< "idle_timeout:" << idle_timeout.ToMilliseconds()
<< " handshake_timeout:" << handshake_timeout.ToMilliseconds();
// Adjust the idle timeout on client and server to prevent clients from
// sending requests to servers which have already closed the connection.
if (perspective_ == Perspective::IS_SERVER) {
idle_timeout = idle_timeout + QuicTime::Delta::FromSeconds(3);
} else if (idle_timeout > QuicTime::Delta::FromSeconds(1)) {
idle_timeout = idle_timeout - QuicTime::Delta::FromSeconds(1);
}
handshake_timeout_ = handshake_timeout;
idle_network_timeout_ = idle_timeout;
SetTimeoutAlarm();
}
void QuicConnection::CheckForTimeout() {
QuicTime now = clock_->ApproximateNow();
QuicTime time_of_last_packet =
std::max(time_of_last_received_packet_, last_send_for_timeout_);
// |delta| can be < 0 as |now| is approximate time but |time_of_last_packet|
// is accurate time. However, this should not change the behavior of
// timeout handling.
QuicTime::Delta idle_duration = now - time_of_last_packet;
QUIC_DVLOG(1) << ENDPOINT << "last packet "
<< time_of_last_packet.ToDebuggingValue()
<< " now:" << now.ToDebuggingValue()
<< " idle_duration:" << idle_duration.ToMicroseconds()
<< " idle_network_timeout: "
<< idle_network_timeout_.ToMicroseconds();
if (idle_duration >= idle_network_timeout_) {
const string error_details = "No recent network activity.";
QUIC_DVLOG(1) << ENDPOINT << error_details;
CloseConnection(QUIC_NETWORK_IDLE_TIMEOUT, error_details,
idle_timeout_connection_close_behavior_);
return;
}
if (!handshake_timeout_.IsInfinite()) {
QuicTime::Delta connected_duration = now - stats_.connection_creation_time;
QUIC_DVLOG(1) << ENDPOINT
<< "connection time: " << connected_duration.ToMicroseconds()
<< " handshake timeout: "
<< handshake_timeout_.ToMicroseconds();
if (connected_duration >= handshake_timeout_) {
const string error_details = "Handshake timeout expired.";
QUIC_DVLOG(1) << ENDPOINT << error_details;
CloseConnection(QUIC_HANDSHAKE_TIMEOUT, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
}
SetTimeoutAlarm();
}
void QuicConnection::SetTimeoutAlarm() {
QuicTime time_of_last_packet =
std::max(time_of_last_received_packet_, time_of_last_sent_new_packet_);
time_of_last_packet =
std::max(time_of_last_received_packet_, last_send_for_timeout_);
QuicTime deadline = time_of_last_packet + idle_network_timeout_;
if (!handshake_timeout_.IsInfinite()) {
deadline = std::min(deadline,
stats_.connection_creation_time + handshake_timeout_);
}
timeout_alarm_->Update(deadline, QuicTime::Delta::Zero());
}
void QuicConnection::SetPingAlarm() {
if (perspective_ == Perspective::IS_SERVER) {
// Only clients send pings.
return;
}
if (!visitor_->HasOpenDynamicStreams()) {
ping_alarm_->Cancel();
// Don't send a ping unless there are open streams.
return;
}
ping_alarm_->Update(clock_->ApproximateNow() + ping_timeout_,
QuicTime::Delta::FromSeconds(1));
}
void QuicConnection::SetRetransmissionAlarm() {
if (delay_setting_retransmission_alarm_) {
pending_retransmission_alarm_ = true;
return;
}
QuicTime retransmission_time = sent_packet_manager_.GetRetransmissionTime();
retransmission_alarm_->Update(retransmission_time,
QuicTime::Delta::FromMilliseconds(1));
}
void QuicConnection::MaybeSetMtuAlarm(QuicPacketNumber sent_packet_number) {
// Do not set the alarm if the target size is less than the current size.
// This covers the case when |mtu_discovery_target_| is at its default value,
// zero.
if (mtu_discovery_target_ <= max_packet_length()) {
return;
}
if (mtu_probe_count_ >= kMtuDiscoveryAttempts) {
return;
}
if (mtu_discovery_alarm_->IsSet()) {
return;
}
if (sent_packet_number >= next_mtu_probe_at_) {
// Use an alarm to send the MTU probe to ensure that no ScopedPacketBundlers
// are active.
mtu_discovery_alarm_->Set(clock_->ApproximateNow());
}
}
QuicConnection::ScopedPacketBundler::ScopedPacketBundler(
QuicConnection* connection,
AckBundling ack_mode)
: connection_(connection),
already_in_batch_mode_(connection != nullptr &&
connection->packet_generator_.InBatchMode()) {
if (connection_ == nullptr) {
return;
}
// Move generator into batch mode. If caller wants us to include an ack,
// check the delayed-ack timer to see if there's ack info to be sent.
if (!already_in_batch_mode_) {
QUIC_DVLOG(2) << "Entering Batch Mode.";
connection_->packet_generator_.StartBatchOperations();
}
if (ShouldSendAck(ack_mode)) {
QUIC_DVLOG(1) << "Bundling ack with outgoing packet.";
DCHECK(ack_mode == SEND_ACK || connection_->ack_frame_updated() ||
connection_->stop_waiting_count_ > 1);
connection_->SendAck();
}
}
bool QuicConnection::ScopedPacketBundler::ShouldSendAck(
AckBundling ack_mode) const {
switch (ack_mode) {
case SEND_ACK:
return true;
case SEND_ACK_IF_QUEUED:
return connection_->ack_queued();
case SEND_ACK_IF_PENDING:
return connection_->ack_alarm_->IsSet() ||
connection_->stop_waiting_count_ > 1;
case NO_ACK:
return false;
default:
QUIC_BUG << "Unsupported ack_mode.";
return true;
}
}
QuicConnection::ScopedPacketBundler::~ScopedPacketBundler() {
if (connection_ == nullptr) {
return;
}
// If we changed the generator's batch state, restore original batch state.
if (!already_in_batch_mode_) {
QUIC_DVLOG(2) << "Leaving Batch Mode.";
connection_->packet_generator_.FinishBatchOperations();
// Once all transmissions are done, check if there is any outstanding data
// to send and notify the congestion controller if not.
//
// Note that this means that the application limited check will happen as
// soon as the last bundler gets destroyed, which is typically after a
// single stream write is finished. This means that if all the data from a
// single write goes through the connection, the application-limited signal
// will fire even if the caller does a write operation immediately after.
// There are two important approaches to remedy this situation:
// (1) Instantiate ScopedPacketBundler before performing multiple subsequent
// writes, thus deferring this check until all writes are done.
// (2) Write data in chunks sufficiently large so that they cause the
// connection to be limited by the congestion control. Typically, this
// would mean writing chunks larger than the product of the current
// pacing rate and the pacer granularity. So, for instance, if the
// pacing rate of the connection is 1 Gbps, and the pacer granularity is
// 1 ms, the caller should send at least 125k bytes in order to not
// be marked as application-limited.
connection_->CheckIfApplicationLimited();
}
DCHECK_EQ(already_in_batch_mode_,
connection_->packet_generator_.InBatchMode());
}
QuicConnection::ScopedRetransmissionScheduler::ScopedRetransmissionScheduler(
QuicConnection* connection)
: connection_(connection),
already_delayed_(connection_->delay_setting_retransmission_alarm_) {
connection_->delay_setting_retransmission_alarm_ = true;
}
QuicConnection::ScopedRetransmissionScheduler::
~ScopedRetransmissionScheduler() {
if (already_delayed_) {
return;
}
connection_->delay_setting_retransmission_alarm_ = false;
if (connection_->pending_retransmission_alarm_) {
connection_->SetRetransmissionAlarm();
connection_->pending_retransmission_alarm_ = false;
}
}
HasRetransmittableData QuicConnection::IsRetransmittable(
const SerializedPacket& packet) {
// Retransmitted packets retransmittable frames are owned by the unacked
// packet map, but are not present in the serialized packet.
if (packet.transmission_type != NOT_RETRANSMISSION ||
!packet.retransmittable_frames.empty()) {
return HAS_RETRANSMITTABLE_DATA;
} else {
return NO_RETRANSMITTABLE_DATA;
}
}
bool QuicConnection::IsTerminationPacket(const SerializedPacket& packet) {
if (packet.retransmittable_frames.empty()) {
return false;
}
for (const QuicFrame& frame : packet.retransmittable_frames) {
if (frame.type == CONNECTION_CLOSE_FRAME) {
return true;
}
if (save_crypto_packets_as_termination_packets_ &&
frame.type == STREAM_FRAME &&
frame.stream_frame->stream_id == kCryptoStreamId) {
return true;
}
}
return false;
}
void QuicConnection::SetMtuDiscoveryTarget(QuicByteCount target) {
mtu_discovery_target_ = GetLimitedMaxPacketSize(target);
}
QuicByteCount QuicConnection::GetLimitedMaxPacketSize(
QuicByteCount suggested_max_packet_size) {
if (!peer_address_.IsInitialized()) {
QUIC_BUG << "Attempted to use a connection without a valid peer address";
return suggested_max_packet_size;
}
const QuicByteCount writer_limit = writer_->GetMaxPacketSize(peer_address());
QuicByteCount max_packet_size = suggested_max_packet_size;
if (max_packet_size > writer_limit) {
max_packet_size = writer_limit;
}
if (max_packet_size > kMaxPacketSize) {
max_packet_size = kMaxPacketSize;
}
return max_packet_size;
}
void QuicConnection::SendMtuDiscoveryPacket(QuicByteCount target_mtu) {
// Currently, this limit is ensured by the caller.
DCHECK_EQ(target_mtu, GetLimitedMaxPacketSize(target_mtu));
// Send the probe.
packet_generator_.GenerateMtuDiscoveryPacket(target_mtu, nullptr);
}
void QuicConnection::DiscoverMtu() {
DCHECK(!mtu_discovery_alarm_->IsSet());
// Check if the MTU has been already increased.
if (mtu_discovery_target_ <= max_packet_length()) {
return;
}
// Calculate the packet number of the next probe *before* sending the current
// one. Otherwise, when SendMtuDiscoveryPacket() is called,
// MaybeSetMtuAlarm() will not realize that the probe has been just sent, and
// will reschedule this probe again.
packets_between_mtu_probes_ *= 2;
next_mtu_probe_at_ = sent_packet_manager_.GetLargestSentPacket() +
packets_between_mtu_probes_ + 1;
++mtu_probe_count_;
QUIC_DVLOG(2) << "Sending a path MTU discovery packet #" << mtu_probe_count_;
SendMtuDiscoveryPacket(mtu_discovery_target_);
DCHECK(!mtu_discovery_alarm_->IsSet());
}
void QuicConnection::OnPeerMigrationValidated() {
if (active_peer_migration_type_ == NO_CHANGE) {
QUIC_BUG << "No migration underway.";
return;
}
highest_packet_sent_before_peer_migration_ = 0;
active_peer_migration_type_ = NO_CHANGE;
}
// TODO(jri): Modify method to start migration whenever a new IP address is seen
// from a packet with sequence number > the one that triggered the previous
// migration. This should happen even if a migration is underway, since the
// most recent migration is the one that we should pay attention to.
void QuicConnection::StartPeerMigration(
PeerAddressChangeType peer_migration_type) {
// TODO(fayang): Currently, all peer address change type are allowed. Need to
// add a method ShouldAllowPeerAddressChange(PeerAddressChangeType type) to
// determine whether |type| is allowed.
if (active_peer_migration_type_ != NO_CHANGE ||
peer_migration_type == NO_CHANGE) {
QUIC_BUG << "Migration underway or no new migration started.";
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Peer's ip:port changed from "
<< peer_address_.ToString() << " to "
<< last_packet_source_address_.ToString()
<< ", migrating connection.";
highest_packet_sent_before_peer_migration_ =
sent_packet_manager_.GetLargestSentPacket();
peer_address_ = last_packet_source_address_;
active_peer_migration_type_ = peer_migration_type;
// TODO(jri): Move these calls to OnPeerMigrationValidated. Rename
// OnConnectionMigration methods to OnPeerMigration.
visitor_->OnConnectionMigration(peer_migration_type);
sent_packet_manager_.OnConnectionMigration(peer_migration_type);
}
bool QuicConnection::ack_frame_updated() const {
return received_packet_manager_.ack_frame_updated();
}
QuicStringPiece QuicConnection::GetCurrentPacket() {
if (current_packet_data_ == nullptr) {
return QuicStringPiece();
}
return QuicStringPiece(current_packet_data_, last_size_);
}
bool QuicConnection::MaybeConsiderAsMemoryCorruption(
const QuicStreamFrame& frame) {
if (frame.stream_id == kCryptoStreamId ||
last_decrypted_packet_level_ != ENCRYPTION_NONE) {
return false;
}
if (perspective_ == Perspective::IS_SERVER &&
frame.data_length >= sizeof(kCHLO) &&
strncmp(frame.data_buffer, reinterpret_cast<const char*>(&kCHLO),
sizeof(kCHLO)) == 0) {
return true;
}
if (perspective_ == Perspective::IS_CLIENT &&
frame.data_length >= sizeof(kREJ) &&
strncmp(frame.data_buffer, reinterpret_cast<const char*>(&kREJ),
sizeof(kREJ)) == 0) {
return true;
}
return false;
}
// Uses a 25ms delayed ack timer. Also helps with better signaling
// in low-bandwidth (< ~384 kbps), where an ack is sent per packet.
// Ensures that the Delayed Ack timer is always set to a value lesser
// than the retransmission timer's minimum value (MinRTO). We want the
// delayed ack to get back to the QUIC peer before the sender's
// retransmission timer triggers. Since we do not know the
// reverse-path one-way delay, we assume equal delays for forward and
// reverse paths, and ensure that the timer is set to less than half
// of the MinRTO.
// There may be a value in making this delay adaptive with the help of
// the sender and a signaling mechanism -- if the sender uses a
// different MinRTO, we may get spurious retransmissions. May not have
// any benefits, but if the delayed ack becomes a significant source
// of (likely, tail) latency, then consider such a mechanism.
const QuicTime::Delta QuicConnection::DelayedAckTime() {
return QuicTime::Delta::FromMilliseconds(
std::min(kMaxDelayedAckTimeMs, kMinRetransmissionTimeMs / 2));
}
void QuicConnection::CheckIfApplicationLimited() {
if (queued_packets_.empty() &&
!sent_packet_manager_.HasPendingRetransmissions() &&
!visitor_->WillingAndAbleToWrite()) {
sent_packet_manager_.OnApplicationLimited();
}
}
void QuicConnection::SetStreamNotifier(
StreamNotifierInterface* stream_notifier) {
sent_packet_manager_.SetStreamNotifier(stream_notifier);
}
void QuicConnection::SetDataProducer(
QuicStreamFrameDataProducer* data_producer) {
framer_.set_data_producer(data_producer);
}
} // namespace net
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